Liquid crystal display (LCD) and organic light-emitting diode (OLED) display images by controlling the light transmittance of liquid crystals (LCs) through electric field, or control organic luminescent material to display images through currents. Such displays generally need to realize the driving and the control of pixels through thin-film transistor (TFT) array substrate.
In order to achieve high resolution requirements, the current TFT array substrate mostly adopt low-temperature polysilicon (LTPS) manufacturing process. Due to the characteristics of high electron mobility, good subthreshold swing, big on/off state current ratio, low power consumption, can be applied to flexible OLED substrate, etc., LTPS has aroused widespread concern in recent years. Due to the conventional LTPS production utilizes excimer laser annealing (ELA) to crystallize, which the machine is expensive, the production cost is high, and cannot produce large sized display panel because of poor homogeneity in ELA crystallization which tend to cause uneven brightness. A new solid phase crystallization (SPC) is began to attract the attention of the industry since it is low in cost and has good crystal homogeneity, and can significantly reduce the temperature and the time required for crystallization if a certain amount of boron ion is implanted before crystallization.
As shown in FIG. 1, the conventional production method of LTPS implants boron ion into amorphous silicon, and deal with the amorphous silicon through rapid thermal annealing. The upper surface of the amorphous silicon will form a polysilicon conductor layer 101 of a small impedance, and the lower portion will form a semiconductor-like polysilicon layer 102. Metal electrode(s) of a source drain layer 103 are utilized to perform dry etching for a mask, so as to etch away the polysilicon conductor layer 101 on the upper surface of a channel area to form a channel, and finally a passivation layer 104 is covered on to completed the TFT device. However, since the source drain layer 103 and the semiconductor-like polysilicon layer 102 of the lower portion are in contact, which will increase the leakage current path so that the leakage current is increased, and the characteristics of the TFT is affected.
Therefore, it is necessary to provide an array substrate and a manufacturing method thereof to resolve the above-mentioned technical problem.